Matter tracking system

ABSTRACT

A system is described that can detect, track and analyze a bubble of a secondary substance contained within a primary substance along a part of a fluid line. For example, the system can detect the presence of the bubble within the primary substance along the part of the fluid line, which can include assigning a digital signature to the bubble. In addition, the system can track the movement of the bubble in order to ensure that the bubble is accounted for only once as it passes through the part of the fluid line. Furthermore, the system can analyze the bubble, such as determine its direction of travel, speed of travel, volume and size.

CROSS REFERENCE TO RELATED APPLICATION

This application is a continuation of U.S. application Ser. No.14/677,789 filed Apr. 2, 2015, entitled “Systems and Methods forTracking Particles in a Fluid Flow”, the disclosure of which isincorporated herein by reference.

TECHNICAL FIELD

The subject matter described herein relates to a system for detecting,tracking and analyzing a secondary substance, which can be in the formof a bubble, within a primary substance contained within a fluid line.

BACKGROUND

Intravenous (IV) systems that deliver fluid to patients typically employthe use of an air-in-line (AIL) sensor that can detect air passingthrough a fluid line. AIL sensors are an important part of an infusionsystem as they alert care givers when dangerous amount of air may bepassing to a patient. However, traditional AIL sensors suffer fromseveral limitations; specifically, they are not able to detect whetheran air bubble being sensed is the same air bubble that was previouslysensed, and they are generally not ideal for sensing objects other thanair. For example, a bubble can become trapped in a fluid line andoscillate within the fluid line. A traditional AIL sensor may be able todetect the trapped bubble, however, the traditional AIL sensor cannotdistinguish a trapped air bubble and will account for the trapped airbubble more than once. This can result in incorrect calculations relatedto the amount of air passing through the fluid line. Also, a traditionalAIL sensor is not well-suited for detecting a secondary substance thatis not air, that will therefore be less likely be able to alert a caregiver of a non-air secondary substance within the primary substance.

SUMMARY

Aspects of the current subject matter can include systems for trackingsecondary substances, which can be in the form of a bubble, in a fluidline. In one aspect, the system an include a light source positionedadjacent the fluid line for directing light to a part of the fluid lineand an image capturing device positioned adjacent the fluid line andconfigured to capture a first image of the part of the fluid line. Thesystem can further include a processing system configured to process thefirst image for detecting a secondary substance within a primarysubstance, wherein the secondary substance is in the form of a bubble.

In some variations, one or more of the following features can optionallybe included in any feasible combination. In some embodiments, theprocessing system can be configured to create a digital signature of thebubble, with the digital signature identifying an outline of the bubblethat is used to track and analyze the bubble. In addition, theprocessing system can be further configured to identify a first locationof the bubble within the first image. The image capturing device can beconfigured to capture a second image of the part of the fluid line andthe processing system can be configured to analyze the second image andidentify a second location of the bubble within the second image. Theprocessing system can be further configured to calculate a distancebetween the first location and the second location and determine if thedistance is within a predetermined range, wherein the predeterminedrange is dependent upon a fluid flow rate within the fluid line.Additionally, the image capturing device can be one or more of a digitalcamera, an infrared camera, and a video camera. Furthermore, the lightcan include infrared light and the image capturing device can bepositioned at an angle from the light source relative to the fluid line.

In some embodiments of the system, the image capturing device can bepositioned in line with the light source and the system can furtherinclude a background positioned on an opposite side of the fluid linefrom the image capturing device and light source. The processing systemcan be further configured to identify a refraction of the light throughat least one of the primary substance and the secondary substance. Theframe rate of the image capturing device can be based on the fluid flowrate. The processing system can be further configured to determine aproperty of the bubble, wherein the property includes one or more of aspeed of travel, a direction of travel, a volume, a size, and a type ofsubstance comprising the bubble.

In another aspect, a method of the system can include capturing a firstimage of a part of a fluid line containing a primary substance with animage capturing device and determining whether the fluid line contains asecondary substance, with the secondary substance being in the form of abubble. In addition, the method can include identifying, with aprocessing system, a first location of the bubble within the first imageand capturing a second image of the part of the fluid line with theimage capturing device. Additionally, the method can includeidentifying, with the processing system, a second location of the bubblewithin the second image.

In some variations of the method, one or more of the following canoptionally be included. For example, the method can further includecalculating a distance between the first location and the secondlocation. In addition, the method can include comparing the calculateddistance with a predetermined range, wherein the predetermined range isdependent on a flow rate within the fluid line. Additionally, the methodcan include adjusting a frame rate of the image capturing device basedon the comparison of the calculated distance with the predeterminedrange. Furthermore, the method can include analyzing the bubble in atleast one of the first image and the second image in order to determinea property of the bubble, wherein the property includes one or more of aspeed of travel, a direction of travel, a volume, a size, and a type ofsubstance comprising the bubble. The method can further includeilluminating a part of a fluid line with light from a light source.

The details of one or more variations of the subject matter describedherein are set forth in the accompanying drawings and the descriptionbelow. Other features and advantages of the subject matter describedherein will be apparent from the description and drawings, and from theclaims.

DESCRIPTION OF DRAWINGS

The accompanying drawings, which are incorporated in and constitute apart of this specification, show certain aspects of the subject matterdisclosed herein and, together with the description, help explain someof the principles associated with the disclosed implementations. In thedrawings,

FIG. 1 shows an implementation of a bubble tracking system, including animage capturing device and a light source positioned adjacent a fluidline.

FIG. 2 shows another implementation of a bubble tracking system, whichincludes the image capturing device positioned in line with the lightsource.

FIG. 3 shows an implementation of a processing system of the bubbletracking system, with the processing system being configured to processthe images captured by the image capturing device for detecting,tracking and analyzing at least one substance contained in the fluidline.

FIG. 4A shows an example of a bubble of a secondary substance in a firstposition within a part of the fluid line.

FIG. 4B shows an example of the bubble of FIG. 4A in a second positionwithin the part of the fluid line.

FIG. 5 shows an example of a first image and a second image taken by theimage capturing device that are analyzed by the processing system inorder to detect, track and analyze at least the bubble of secondarysubstance within the fluid line.

FIG. 6 shows a process flow diagram illustrating aspects of a methodhaving one or more features consistent with implementations of thecurrent subject matter.

When practical, similar reference numbers denote similar structures,features, or elements.

DETAILED DESCRIPTION

The current subject matter is directed to a system that can detect,track and analyze a secondary substance (e.g., air) contained within aprimary substance (e.g., saline solution) along a part of a fluid line.For example, the system can detect and identify the presence of an airbubble within the primary substance, which can also include assigning adigital signature to the bubble. In addition, the system can track themovement of the bubble in order to ensure that the bubble is accountedfor only once as it passes through the fluid line. Furthermore, thesystem can analyze the bubble, such as determine its direction oftravel, speed of travel, volume, size, etc. The system can also detectdensity differences between the primary and secondary fluids whichenables the system to determine with a secondary infusion has finishedand when a primary infusion begins. The system can improve the accuracyof measuring an amount of a secondary substance that passes through thefluid line by implementing improved systems, methods and devices fordetecting, tracking and analyzing the secondary substance, as will bedescribed in greater detail below.

For example, the system can provide improved ways in which to detect,track and analyze how much secondary substance, such as air (i.e., airbubbles), passes through a defined portion of the fluid line and movingin a path toward a patient. This can allow a device or system thatdelivers a primary fluid (e.g., saline solution) to a patient toefficiently and effectively keep track of how much air is passes throughthe fluid line and is believed to be delivered to a patient. It can beimportant to keep track of the amount of air that a patient receivesthrough an IV line to ensure that the patient is not at risk for an airembolism, which can cause medical complications (e.g., heart attack,stroke, etc.).

In some traditional AIL sensors it can be difficult to keep an accurateaccount of how many bubbles or how much air is delivered to the patient.For example, bubbles can get trapped and oscillate in the fluid line,which can cause, for example, AIL sensors to account for a single bubblemore than once. Also, some current AIL sensors are not able to detectsmall volume bubbles of a secondary substance. For example, some currentAIL sensors cannot detect volumes that are less than 30 microliters. Asa result, these AIL sensors can create false alarms as to an amount ofair that has passed through the fluid line, which can interrupt therapyand unnecessarily prolong and complicate treatment of a patient, or theycan create an inaccurate measurement of the amount of air that haspassed through the fluid line, potentially endangers the patient. Incontrast, the present system described herein provides systems andmethods for tracking individual bubbles along a fluid path in order toensure that each bubble is accounted for only once. In addition,measurements of each bubble can be made with system that allows thesystem to determine an amount of the secondary substance (e.g., air) ineach bubble, as well as efficiently and effectively calculate a totalamount of the secondary substance that passes through the fluid line.This information can be used in order to calculate accurate amounts ofsecondary substance that is delivered to the patient and provideaccurate information to caretakers and patients, such as warnings as tothe amount of secondary substance that has been or will be delivered tothe patient.

As will be discussed in greater detail below, the system can identifyand calculate any number of features related to the secondary substance,such as direction of movement, volume, speed, merging of bubbles,dividing of bubbles, etc. Furthermore, the system can track one or morebubbles simultaneously and can detect more than two substances (i.e.,more than just the primary substance and secondary substance).Therefore, although examples discussed herein may reference a singlebubble or a primary substance and/or a secondary substance, the systemis not limited to such examples.

Some implementations of the system can include an image capturing deviceand a light source, with both the image capturing device and lightsource positioned adjacent the fluid line. The fluid line can containfluid (e.g., primary and secondary substances) that can be captured bythe image capturing device with the assistance of the light sourceilluminating a part of the fluid line. A processing system can processimages captured by the image capturing device in order to determine thepresence of either a primary substance or a secondary substance (whichcan be in the form of bubbles). In addition, the captured images can beprocessed by a processing system in order to track individual bubbles aswell as determine properties associated with each of the bubbles (e.g.,direction of travel, speed of travel, oscillation, volume, size, etc.).The image capturing device can capture multiple frames of the bubblepassing through the fluid line at a rate such that the bubble will nevermove farther than its diameter from one frame to the next. In thismanner the system is able to track the bubble from one frame to the nextand is able to reliably and consistently determine the direction, speedand general movement of the bubble.

FIG. 1 illustrates an implementation of a system 100 that includes animage capturing device 102 and a light source 104 positioned adjacent afluid line 106. For example, the fluid line 106 can be in fluidcommunication with a part of an infusion system or device that deliversa primary substance 107 (e.g., water) to a patient. The system 100 canbe configured to efficiently and effectively detect, track, and analyzeone or more secondary substances 109 (e.g., air) contained within theprimary substance 107, which can travel in the form of a bubble 111.This can assist with ensuring that an unsafe volume of the secondarysubstance 109 is not delivered to the patient. Although examples andimplementations are described herein relating to a primary substance 107and a secondary substance 109, any number of substances can be detected,tracked and analyzed with the system 100. In addition, although bubblesare described in examples as being detected, tracked, and analyzed usingthe system 100, the system 100 can detect any number of substances(e.g., foreign materials) in any number of shapes or formations.

The light source 104 can provide one or more of a variety of types oflight, such as infrared light, which can illuminate the part of fluidline 106 the image capturing device 102 is positioned to capture. Inaddition, the light from the light source 104 can assist the imagecapturing device 102 with capturing properties associated with primarysubstance 107 and secondary substance 109, such as allowing the imagecapturing device 102 to capture reflective and/or refractive propertiesof the primary substance 107 and/or secondary substance 109. This canassist a processing system 108 associated with the system 100 to processimages captured by the image capturing device 102 in order to detect,track and analyze bubbles 111 in the fluid line 106.

The light source 104 can be any of a variety of light sources, such asan infrared light source. Additionally, more than one light source 104can be used for lighting various angles and/or positions along the fluidline 106. The light delivered from the light source 104 can be analyzedby the processing system 108 and/or image capturing device 102. Forexample, the refraction of the light as it passes through either theprimary substance 107 or the secondary substance 109 can assist thesystem 100 with detecting the presence of either the primary substance107 or the secondary substance 109, as well as identifying the locationof a bubble 511 of secondary substance 109. Furthermore, thisinformation can be used by the processing system 108 to assist withcreating a digital signature of the bubble 111.

The image capturing device 102 can include a digital camera, an infraredcamera, or a video camera. In addition, the image capturing device 102can be positioned in a variety of positions relative to either the fluidline 106 or the light source 104. As shown in FIG. 1, the image capturedevice 102 can be positioned at an angle, such as a 90 degree angle,from the light source 104 relative to the fluid line 106. In addition,some implementations of the system 100 can include more than one imagecapturing device 102, such as for capturing various angles and/orpositions along the fluid line 106.

FIG. 2 shows another implementation of a system 200, which can includean image capturing device 202 positioned in line with a light source 204adjacent to a fluid line 206. In addition, the system 200 can include abackground 210, such as a dark (e.g., black) background, positioned onan opposite side of the fluid line 206 from the image capturing device202 and light source 204. The background 210 can assist with cutting outbackground light, which can allow for clearer images to be captured bythe image capturing device 202. The background 210 also enables thesystem to filter out inconsistencies with the image capturing device 202and enables the calibration of the image capturing device 202 in orderto effectively operate with multiple types of tubing.

FIG. 3 shows an implementation of a system 300 including a processingsystem 308 configured to process images captured by the image capturingdevice 302 for detecting, tracking and analyzing bubbles 311 of asecondary substance 309 contained within a primary substance 307. Forexample, the processing system 308 can include a controller 312 forcontrolling the image capturing device 302, such as the rate at whichthe image capturing device 302 captures images (i.e., frame rate). Theframe rate can be set or adjusted by the controller 312 based on a fluidflow rate within the fluid line 306. For example, if the flow ratewithin the fluid line 306 increases, the controller 312 can increase theframe rate. This can allow the image capture device 302 to captureenough images of the fluid line 306 such that each bubble 311 of thesecondary substance 309 can be detected, tracked and analyzed. By way offurther example, if the flow rate within the fluid line 306 decreases,the controller 312 can decrease the frame rate. The frame rate can beset or adjusted to ensure that fluid flowing within the fluid line 306,including any bubbles 311, is captured in at least one image by theimage capturing device 302, which can allow the processing system 308 toanalyze each of the bubbles 311 that flow through the fluid line.

The processing system 308 can further include an algorithm 313 that canassist with processing the images captured by the image capturing device302. For example, the algorithm 313 can assist with determining alocation of the bubble 311 captured by the image capturing device 314.In addition, the algorithm 313 can assist with creating a digitalsignature of the bubble 311, which can assist with tracking the bubble311 in subsequent images. The digital signature can define an outlineand/or size of the bubble, which can be determined based on a refractionof light through the bubble 311 that can be detected by either the imagecapturing device 302 or the processing system 308, such as the algorithm313. Additionally, the algorithm 313 can assist with determining anapproximate size and/or volume of the bubble 311, which can be used bythe system 300 to keep track of how much (i.e., volume) of the secondarysubstance 309 is being, or has been, delivered to the patient. Althoughthe processing system is described by way of example, as having a singlealgorithm, the processing system can have more than one algorithm.

FIG. 4A shows an example of a bubble 411 of a secondary substance 409 ina first position within a part of the fluid line 406. The first positioncan be referenced based on an acquisition window or frame 415 of acaptured image taken by the image capturing device 102. The frame 415can be the same location along the fluid line 406 for each imagecaptured by the image capturing device 102. As such, the frame 415 canbe used as a reference point for locating and tracking bubbles 411captured within each image.

FIG. 4B shows an example of the bubble 411 shown in FIG. 4A, but in asecond position within the frame 415. The processing system 108 canassist with locating and identifying the first position and the secondposition of the bubble 411 within the frame 415 for each image, as wellas compare the first position and second position in order to determinecharacteristics of the bubble, such as what direction the bubble 411 istraveling (including back and forth or oscillating movements) and thespeed at which the bubble 411 is traveling. The processing system 108can also assign a digital signature to the bubble 411 in order to assistwith tracking the location and movements of each bubble 411.Furthermore, the processing system 108 can use the digital signature todetermine any number of features associated with the bubble 411, such asthe size and volume of each bubble 411, or when a bubble splits apart orcoalesces.

FIG. 5 shows an example of a first image 520 and a second image 522taken by the image capturing device 102 that can be processed by theprocessing system 108 in order to detect, track and analyze at least thebubble 511 of secondary substance 509 within the fluid line. The firstimage 520 can have the same frame 524 as the second image 522 such thatthe frame 524 can provide a reference for the processing system 108 toidentify a first position of the bubble 511 within the first image 520and a second position of the bubble 511 within the second image 522. Theprocessing system 108 can then calculate a distance (d) between thefirst position and the second position of the bubble 511. Thiscalculated distance (d) can be compared against a predetermined rangethe bubble could travel, which can be based on a fluid flow rate in thefluid line.

For example, the predetermined range can indicate a minimum and maximumdistance the bubble 511 can travel given the flow rate of fluid within apart of the fluid line 106. As such, if the calculated distance (d) isoutside of the predetermined range, then the processing system 108 candetermine that more than one bubble traveled past the part of the fluidline. However, if the calculated distance (d) is within thepredetermined range, then the processing system 108 can determine, alongwith other indications (e.g., digital signature of the bubble), that thesame bubble is being tracked. Additional features associated with theprocessing system 108 can also assist with detecting and tracking eachbubble 511, such as the digital signature assigned to each bubble. Thedigital signature can assist in keeping track of each bubble 511 andensure that each bubble 511 is counted only once. This can ensure thateven bubbles that oscillate and/or get trapped within the fluid line 106are not repeatedly accounted for, which can create false information(e.g., false alarms). The digital signature can also assist in trackingeach bubble 511, including during merging of two or more bubbles and/ordividing of one or more bubbles.

In some implementations, the detection and identification of propertiesassociated with either the primary substance or the secondary substance,including properties associated with the bubble, can be based on a totalinternal reflection (“TIR”) principle derived from Snell's Law and theFresnel Equations. For example, the TIR principle can specify therelative amount of light reflected and transmitted by a surface and canassist with describing the behavior of light, such as from the lightsource 104, as it passes the surface between two media (e.g., primaryand secondary substances) with different refraction indices. The TIRprincipal can be included in some of the processing associated with theprocessing system, such as included in an algorithm for determining aproperty of either the primary substance or secondary substance (e.g.,type of substance, outline or size of substance, etc.).

FIG. 6 shows a process flow chart 600 illustrating features of a methodconsistent with one or more implementations of the current subjectmatter. It will be understood that other implementations may include orexclude certain features. At 602, a first image of a part of the fluidline can be captured with an image capturing device. The fluid line cancontain a primary substance and a secondary substance, with thesecondary substance being in the form of a bubble. Then, at 604, theprocessing system can identify a first location of the bubble within thefirst image. At 606, the image capturing device can capture a secondimage of the part of the fluid line. Then, at 608 the processing systemcan identify a second location of the bubble within the second image.

Furthermore, the processing system can also calculate a distance betweenthe first location and the second location of the bubble and determinewhether the calculated distance is within a predetermined range. Thepredetermined range can be dependent upon a flow rate within the fluidline. The frame rate of the image capturing device can be adjusted basedon the whether the calculated distance is within the predeterminedrange. In addition, the processing system can analyze the bubble ineither the first image or second image in order to determine one or moreof a speed of travel of the bubble, a direction of travel of the bubble,a volume of the bubble, a size of the bubble, and a type of substancecomprising the bubble. The method can further include illuminating apart of the fluid line with light from a light source and positioningthe image capturing device in various positions relative to the lightsource and fluid line.

In the descriptions above and in the claims, phrases such as “at leastone of” or “one or more of” may occur followed by a conjunctive list ofelements or features. The term “and/or” may also occur in a list of twoor more elements or features. Unless otherwise implicitly or explicitlycontradicted by the context in which it is used, such a phrase isintended to mean any of the listed elements or features individually orany of the recited elements or features in combination with any of theother recited elements or features. For example, the phrases “at leastone of A and B;” “one or more of A and B;” and “A and/or B” are eachintended to mean “A alone, B alone, or A and B together.” A similarinterpretation is also intended for lists including three or more items.For example, the phrases “at least one of A, B, and C;” “one or more ofA, B, and C;” and “A, B, and/or C” are each intended to mean “A alone, Balone, C alone, A and B together, A and C together, B and C together, orA and B and C together.” Use of the term “based on,” above and in theclaims is intended to mean, “based at least in part on,” such that anunrecited feature or element is also permissible.

The implementations set forth in the foregoing description do notrepresent all implementations consistent with the subject matterdescribed herein. Instead, they are merely some examples consistent withaspects related to the described subject matter. Although a fewvariations have been described in detail herein, other modifications oradditions are possible. In particular, further features and/orvariations can be provided in addition to those set forth herein. Forexample, the implementations described above can be directed to variouscombinations and sub-combinations of the disclosed features and/orcombinations and sub-combinations of one or more features further tothose disclosed herein. In addition, the logic flows depicted in theaccompanying figures and/or described herein do not necessarily requirethe particular order shown, or sequential order, to achieve desirableresults. The scope of the following claims may include otherimplementations or embodiments.

What is claimed is:
 1. A method of tracking air flow in an intravenousfluid delivery system that delivers fluid to a patient via a fluid line,comprising: causing a primary substance to flow toward and into apatient through the fluid line, wherein the primary substance contains asecondary substance in the form of a bubble; capturing a first image ofa part of the fluid line containing the primary substance with an imagecapturing device; capturing a second image of the part of the fluid linewith the image capturing device; adjusting a frame rate of the imagecapturing device such that the bubble does not move farther than adiameter of the bubble from the first image to the second image; andanalyzing the bubble in at least one of the first image and the secondimage in order to determine a volume of the secondary substance in thebubble.
 2. The method of claim 1, further comprising: identifying afirst location of the bubble within the first image; and identifying asecond location of the bubble within the second image.
 3. The method ofclaim 2, further comprising calculating a distance between the firstlocation and the second location.
 4. The method of claim 3, furthercomprising comparing the calculated distance with a predetermined range,wherein the predetermined range is dependent on an actual flow ratewithin the fluid line.
 5. The method of claim 4, further comprisingadjusting a frame rate of the image capturing device based on thecomparison of the calculated distance with the predetermined range. 6.The method of claim 1, further comprising analyzing the bubble in atleast one of the first image and the second image in order to determineat least one of a speed of travel of the bubble, a direction of travelof the bubble, and a type of substance of the bubble.
 7. The method ofclaim 1, further comprising illuminating a part of a fluid line withlight from a light source.
 8. The method of claim 7, wherein the imagecapturing device is positioned at an angle from the light sourcerelative to the fluid line.
 9. The method of claim 7, wherein the imagecapturing device is positioned in line with the light source and thebubble tracking system further includes a background positioned on anopposite side of the fluid line from the image capturing device andlight source.
 10. A system for tracking bubbles in a patient fluid lineof an intravenous system that delivers fluid to a patient, comprising: alight source positioned adjacent the fluid line for directing light to apart of the fluid line, wherein the fluid line is intravenouslyconnected to a patient and contains a primary substance flowing towardand into a patient; an image capturing device positioned adjacent thefluid line and configured to capture a first image and capture a secondimage of the part of the fluid line that contains the primary substanceflowing toward and into the patient; a controller configured to adjust aframe rate of the image capturing device based on an actual fluid flowrate of the primary substance in the fluid line; and a processing systemconfigured to: adjust a frame rate of the image capturing device suchthat the bubble does not move farther than a diameter of the bubble fromthe first image to the second image; and analyze the bubble in at leastone of the first image and the second image in order to determine avolume of the secondary substance in the bubble.
 11. The system of claim10, wherein the processing system is further configured to: identify afirst location of the bubble within the first image; and identify asecond location of the bubble within the second image.
 12. The system ofclaim 11, wherein the processing system is further configured tocalculate a distance between the first location and the second location.13. The system of claim 10, wherein the image capturing device is one ormore of a digital camera, an infrared camera, and a video camera. 14.The system of claim 10, wherein the light comprises infrared light. 15.The system of claim 10, wherein the image capturing device is positionedat an angle from the light source relative to the fluid line.
 16. Thesystem of claim 10, wherein the image capturing device is positioned inline with the light source and system further includes a backgroundpositioned on an opposite side of the fluid line from the imagecapturing device and light source.
 17. The system of claim 10, whereinthe processing system is further configured to identify a refraction ofthe light through at least one of the primary substance and thesecondary substance.
 18. The system of claim 10, wherein the processingsystem is further configured to determine a property of the bubble,wherein the property includes one or more of a speed of travel of thebubble, a direction of travel of the bubble, and a type of substance ofthe bubble.